Appendix L: Media Type Registration for image/svg+xml

Contents

L.1.
Introduction

This appendix registers a new MIME media type, "image/svg+xml" in conformance with BCP 13 and W3CRegMedia.

L.2.
Registration of media type image/svg+xml

Type name:

image

Subtype name:

svg+xml

Required parameters:

None.

Optional parameters:

charset

Same as application/xml media type, as specified in [RFC3023] or its successors.

Encoding considerations:

Same as for application/xml. See [RFC3023], section 3.2 or its successors.

Security considerations:

As with other XML types and as noted in [RFC3023] section 10, repeated expansion of maliciously constructed XML entities can be used to consume large amounts of memory, which may cause XML processors in constrained environments to fail.

Several SVG elements may cause arbitrary URIs to be referenced. In this case, the security issues of [RFC3986], section 7, should be considered.

In common with HTML, SVG documents may reference external media such as images, audio, video, style sheets, and scripting languages. Scripting languages are executable content. In this case, the security considerations in the Media Type registrations for those formats shall apply.

In addition, because of the extensibility features for SVG and of XML in general, it is possible that "image/svg+xml" may describe content that has security implications beyond those described here. However, if the processor follows only the normative semantics of the published specification, this content will be outside the SVG namespace and shall be ignored. Only in the case where the processor recognizes and processes the additional content, or where further processing of that content is dispatched to other processors, would security issues potentially arise. And in that case, they would fall outside the domain of this registration document.

Interoperability considerations:

The published specification describes processing semantics that dictate behavior that must be followed when dealing with, among other things, unrecognized elements and attributes, both in the SVG namespace and in other namespaces.

Because SVG is extensible, conformant "image/svg+xml" processors must expect that content received is well-formed XML, but it cannot be guaranteed that the content is valid to a particular DTD or Schema or that the processor will recognize all of the elements and attributes in the document.

SVG has a published Test Suite and associated implementation report showing which implementations passed which tests at the time of the report. This information is periodically updated as new tests are added or as implementations improve.

SVG is used by Web browsers, often in conjunction with HTML; by mobile phones and digital cameras, as a format for interchange of graphical assets in desk top publishing, for industrial process visualization, display signage, and many other applications which require scalable static or interactive graphical capability.

Additional information:

Magic number(s):

File extension(s):

svg

Note that the extension 'svgz' is used as an alias for 'svg.gz'
[RFC1952],
i.e. octet streams of type image/svg+xml, subsequently
compressed with gzip.